As mentioned above, some of the embodiments described herein relate to a multi-use cooking zone which is configured for both searing of food and normal cooking. The cooking technique known as “searing” is well known in the art and is used by many connoisseurs, especially when cooking fish and meat. Searing of food involves the application of direct and intense heat to the food, which causes food to rapidly cook on the outside, but not on the inside. In this manner, the outside surface of the food is slightly singed or burnt, which effectively locks the natural juices and/or marinade into the food. After searing, the meat is usually rare on the inside and can be eaten. Alternatively, the meat can be cooked in a conventional manner to achieve a medium or well done appearance.
Prior art barbecue grills use various means for searing food. For example, some manufacturers incorporate infrared (IR) burners into their barbecue grills, which are capable of producing the intense heat required for searing food. The searing (IR) burners of the prior art grills are typically disposed underneath the cooking surface and replace at least one standard burner. Usually, the IR burner sits below approximately ¼ to ⅓ of the cooking surface while the standard burners sit below approximately ⅔ to ¾ of the cooking surface.
While the prior art IR burners are very effective at searing foods, because of the intense heat they can generate, the IR burners are not very effective at cooking foods in a conventional manner. Even though some IR burners include temperature controls, the low setting for an IR burner is still hotter than the high setting for a typical standard burner. In that respect, IR burners are not typically capable of cooking food slowly at low heat, which is usually required for thick cuts of meat. For this reason, some manufacturers of grills having IR burners recommend first searing the food above the IR burners, and then moving the food over the standard burners to finish cooking the food in a conventional manner. Because the IR burners are not effective at cooking foods conventionally, the portion of the cooking surface which sits above the IR burners is essentially lost space—only the portion of the cooking surface which sits above the standard burner tubes is usable space for conventional grilling.
Accordingly, there is a need in the art for a heat source for a barbecue grill which is capable of providing both the intense heat required for searing of foods and the low heat required for slow cooking. There is also a need in the art for a barbecue grill which is capable of searing foods, but makes more efficient use of the cooking surface as compared to the prior art grills.
One potential solution to the above mentioned problems, which is suggested herein, would be to use a standard burner in combination with a gas flow control valve that has an increased capacity, instead of using an IR burner. While this solution seems “simple” at first glance, this solution has some significant drawbacks. For instance, most valves are configured to provide only 50% of the maximum flow at a low setting. Therefore, increasing the “high” flow capabilities of the valve will also increase the “low” flow capabilities of the valve, thereby having a detrimental effect on the low temperature cooking capabilities of the barbecue grill. For example, a typical valve which is used for larger grill application provides roughly 12,000 BTUH at a high setting and roughly 6,000 BTUH at a low setting. Typical valves which are used for small grill applications provide roughly 6,000 BTUH at a high setting and roughly 3,000 BTUH at a low setting. It can be said then that while the use of a larger “off-the-shelf” valve in combination with a standard burner will be capable of providing the intense heat needed to sear food, such configuration will not be very effective at cooking low and slow.
To effectively utilize the solution proposed above, there is a need in the art for a valve which is capable of providing additional flow capacity at a high setting without having to sacrifice the low end capacity of the valve.
Other embodiments described and claimed herein relate to gas control valves for barbecue grills, which have beneficial features not found in the prior art. Many barbecue grill manufacturers currently use linearly regulated gas valves (or control valves) for adjusting the flow of gas to the burner tube of the grill. These valves generally provide linear flow from a high flow setting to a low flow setting in order to allow the user to vary the heat output of a barbecue grill. These prior art valves are also configured to prevent the interruption of gas flow, for example between high, medium, and low settings, whereby the flame will not be extinguished when the user adjusts the valve. Examples of such gas valves are disclosed in U.S. Pat. No. 6,520,481 (“the '481 patent”) and U.S. Pat. No. 6,845,966 (“the '966 patent”).
Gas valves for barbecue grills typically have four gas flow settings: off, high, medium, and low, typically disposed in that order; i.e. the first setting obtained by rotating the valve stem from the off setting is the high, or maximum, setting. Further rotation of the valve stem would reduce the gas flow (i.e., the heat provided to the cooking chamber) to the medium setting and then, finally, to the low setting. The stem of the valve typically positively engages with the valve body (or valve cover) at the off, high, and low settings. For example, with reference to FIG. 7 of the '481 patent, the valve cap of the '481 patent includes two detents, one at the off setting and one at the high setting, which positively engage with an indexing rod which depends from the valve stem. The valve cap of the '481 patent also includes a vertical stop which positively engages with the indexing rod at the low setting.
A typical valve of the prior art regulates flow by restricting the flow area of the valve. The valves typically include an orifice at the exit of the valve and a valve plug which restricts the flow area at the inlet of the valve (note that some valves have an orifice at the inlet and the valve plug restricts the flow area the outlet of the valve). When the valve is in the fully open, or maximum flow position, the flow area at the inlet of the valve is not restricted. As such, the orifice at the outlet of the valve regulates the flow. When the valve is set to a lower flow position, the valve plug plays a large part in controlling the flow rate of the valve. In the lower flow positions, the valve plug restricts the flow area at the inlet of the valve, providing resistance to the flow.
While the prior art gas control valves successfully regulate gas flow to burner tubes, there are a number of problems with the current gas control valves which have not been solved. For example, it is a widely accepted convention in the industry that gas control valves for barbecue grills require the user to rotate the valve stem 90° from the off setting in order to reach the high, or maximum flow, setting. There are a number of problems associated with this convention. First, significant twisting of the valve stem is required to turn the gas grill on, which is inconvenient for the user. Second, having a large rotational offset between the off setting and the high setting diminishes how finely the user can set the variable flow rate, because it reduces the angular offset between the high and low settings. Although there are a number of innovators in the field, it is believed that none have attempted or all have failed to solve this problem.
Accordingly, there is a need in the art for a valve which reduces the amount of rotation required to turn the grill on. Furthermore, there is a need in the art for a valve having a sear setting, at which the valve provides an increased flow rate sufficient to create searing heat, while also having the capability to provide the high, medium, and low flow rates of the prior art valves. In other words, there is a need in the art for a valve which can not only be used for normal cooking, but also for searing of foods. Even further, there is a need in the art for a valve which not only reduces the amount of rotation required to turn the grill on, but also includes an increased flow capacity to provide searing heat.